The present invention relates to a display unit such as a caption VCR, and more particularly to a caption processing device and method for a display unit with a separate display from a monitor for displaying a video signal on the monitor without being partially covered by a caption signal or OSD (On Screen Display).
In a conventional OSD (On Screen Display) or a video display device for displaying a caption signal together with a video signal, the caption signal is displayed together with the video signal on a TV monitor screen.
Therefore, when the caption signal is displayed with the video signal on the TV screen, the caption signal is displayed in a part of the screen where the video signal is displayed, so that the part of the video signal on the screen where the caption signal is displayed is covered by the caption signal, and thus, the video signal in that part is not displayed on the screen.
As shown in FIG. 1, a conventional VCR includes a data slicer 1, a data processor 2, and a mixer 3.
The data slicer 1 receives a composite video signal (CVS) and outputs caption data, and includes a synchronizing signal separator 11 for separating horizontal synchronizing signals Hsync and vertical synchronizing signals Vsync from a composite video signal input, a data slicer 12 for detecting and outputting a caption signal from the composite videc signal, and a control logic 13 for accepting synchronizing signals Hsync, Vsync from the synchronizing signal separator 11, detecting a caption line which is the 21st line in the odd-numbered fields, and outputting a sample/hold signal S/H for detecting a caption signal to the data slicer 12, and accepting a caption signal CS from the data slicer 12 and outputting caption data CD.
Here, the control logic 13 accepts a horizontal synchronizing signal Hsync and counts the position on a horizontal line and the horizontal lines in each field, uses this data to detect a caption line, detects this to output a sample/hold signal S/H to the data slicer 12, accepts the detected caption signal from the data slicer 12 and outputs caption data.
The data processor 2 processes the caption data outputted by the control logic 13 of the data slicer 1, and includes a central processing unit (CPU) 21, OSD logic 22, video RAM 23, and character ROM 24.
Here, the central processing unit (CPU) 21 receives caption data CD from the control logic 13 and outputs a suitable control signal CTL, and the OSD logic 22 receives the control signal CTL from the CPU 21 and the sample and line count from the data slicer 1 to control the position of the caption displayed.
The mixer 3 mixes the composite video signal CVS reproduces from a video tape and the caption data from the OSD logic 22 and outputs the result to the TV.
Therefore, when the TV is applied of the composite video signal reproduced from a video tape, or of a broadcasting signal received through a VCR tuner, as shown in FIG. 2, the video signal is displayed, together with a caption on a part of the screen where the video signal is displayed.
When the caption VCR with the system described above has its own caption display being selected, the caption VCR composites the caption signal processed into a caption with the main image and displays them on the monitor, on the same time.
Or, when the caption VCR has a caption selection key of TV function keys pressed, caption data CD is extracted by the data slicer 1 from the composite video signal CVS reproduced from the video tape, and the extracted caption data CD is processed into a caption by the data processor 2.
Caption data processed by the data processor 2 is applied to the mixer 3 and mixed with the composite video signal CVS, and the output of the mixer 3 is outputted to the monitor or TV 4.
If the caption selection key is pressed again, the caption disappears from the screen, with only the video signal is displayed.
In FIG. 2, reference number 200 is a VCR, 210 a TV, 220 a caption displayed with a video signal on the same screen, 230 a Braun display (screen), and 240 a cable.
Thus, as shown in FIG. 2, in a conventional caption VCR, part of the video signal displayed on the screen is covered by the caption when the caption is displayed.